ANDREW HALLS, of Magdalen College School, looks at the alternatives on the horizon

Some questions just won't go away. Why has the percentage of A grades at A-Level more than doubled in the last 20 years? Why do results get better and better each year? How is it that with just one wave of the magic wand, New Labour's ministry of educational magic effortlessly turns everything to gold?

For a nation apparently so good at examinations, there appear to be some questions we find very tough indeed.

Why are academics telling us that A-Levels can't distinguish the excellent from the good, or the good from the adequate? Why are so many selector universities setting their own entrance tests? Why are increasing numbers of independent schools looking for an escape route even from GCSEs and taking the International GCSE, especially in mathematics?

The plain fact is that the pointless and tedious coursework of conventional GCSE maths has driven so many children to tears of gibbering boredom, the exam boards are in danger of being reported to the NSPCC.

And why are some of the strongest academic schools in the UK now seriously considering a move out of A-Levels altogether? Not for the international baccalaureate, but for a completely new examination.

The Cambridge International Examinations pre-university diploma is still on the drawing board, but the leading associations of independent schools are getting very interested indeed. Could it be that it will offer our sixth-formers something all too many A-Level syllabuses are neglecting: rigour, yes, but also excitement? Too many exams reward the parading of pre-packaged facts all helpfully outlined in textbooks written by the board's own examiners.

Learning is more organic than this: it depends on the growth and development of ideas, the connections we make between them. There should be a sense of joy and excitement at the eureka moment of discovery, or the back of the net exhilaration of just "getting it".

The Cambridge diploma promises a move away from fool's gold and a return to the gold standard. But what does it actually involve?

Most importantly, it will be free of the often absurd criteria imposed on other syllabuses by Government educational quangos. Students will be able to select three main subjects and a subsidiary very similar to current A-Levels. They will need to complete an extended essay or research task something universities are keen to see.

The emphasis of the diploma will be on depth and subject knowledge. I fear this is no longer true of today's A-Levels.

To qualify for the award, you must already have GCSEs in English, maths, a science, a language and one of the humanities. Unlike the IB, it allows students to concentrate on their strengths any subject combination is possible and there is no compulsion to span the arts and sciences.

Cambridge International Examinations, an offshoot of one of the "big three" exam boards, is backing the project strongly. It plans to publish syllabuses in September and that will be the moment of truth for schools such as mine. If the syllabuses show they will test and reward knowledge, understanding, and even, who knows, originality, we shall be interested. And how much better if they remind us of that love of our subject which encouraged most of us to teach in the first place? No more "delivering assessment objectives", to use the spiritless and materialist jargon of the current system. The other acid test will be the response of the universities. They have been loyal to A-Levels, but they are desperate to see exams which discriminate accurately and which give young minds a sense of their limitless and extraordinary potential. With the support of universities, the diploma could transform post-16 education.

It might just be the answer we've all been looking for.